Vegetation roofing system

ABSTRACT

A vegetation roofing tray comprising an interconnecting lip is provided. The interconnecting lip on the sidewall of a tray engages with a sidewall of an adjacent tray, securely interconnecting the adjacent trays side-by-side together. A securing device penetrating the sidewalls of adjacent trays may also be used to secure the adjacent trays together. A vegetation roofing system is also provided. The system includes two or more trays and an irrigation hose disposed across the trays.

RELATED APPLICATION DATA

This application claims the benefit of U.S. Provisional application Ser.No. 61/027,391, filed Feb. 8, 2008, and is a continuation-in-part ofU.S. patent application Ser. No. 11/621,294, filed Jan. 9, 2007, whichclaimed the benefit of U.S. Provisional application Ser. No. 60/757,768,filed Jan. 9, 2006, the contents of which are herein incorporated byreference in their entirety.

BACKGROUND

1. Technical Field

The invention relates generally to the field of roof coverings.Specifically, the invention relates to a modular system for providingstorm water management and roof-protective vegetation on roof tops.

2. Description of the Related Art

The type of roof covering that is used on a building or dwelling canhave a dramatic impact on the living conditions inside. As an example,roof coverings that provide significant solar energy collection canreduce the amount of heat energy transmitted into the living area of abuilding, which can lead to reduced energy costs (costs associated withcooling the living area) during hot periods. One type of roof coveringthat has received significant interest recently is a so-called ‘greenroof’ system. Green roof systems typically incorporate some type ofvegetation in a roof covering. Green roof systems can lead to reducedenergy costs, due to the insulating effects of the vegetation, reducedstorm-water runoff, due to the water-absorbing nature of the vegetationand accompanying soil, and environmental advantages, due to increasedgreen space in commercial or other populated areas.

One prior art roof covering is disclosed in U.S. Pat. No. 6,606,823 toMcDonough et al (hereinafter “McDonough”). McDonough provides a roofcovering system consisting of modular trays that may be used to holdvegetation, absorbent material, or solar cells. The trays in McDonoughrequire several layers of different materials as well as some type ofballast to weigh down the trays. Further, the McDonough trays have acomplicated and expensive puzzle-type interlocking frame which leaves agap between adjacent trays. These gaps represent un-captured roof areathat does not realize the benefits of the green roof system. Also, thegaps between the trays allow soil mixture to spill out of the trays andonto the frame between the trays. This spilled soil mixture can lead towater pooling underneath the roofing system and subsequent damage to theroof below the roofing system. Consequently, a roofing system that doesnot have gaps between adjacent trays and does not require many layers ofmaterials is desired.

Another prior art system is disclosed in U.S. Pat. No. 6,862,842 toMischo (hereinafter “Mischo”). Mischo provides a modular green roofsystem that consists of pre-seeded panels that have edge flanges forconnection purposes. The flanges of adjacent trays laterally abut orrest on top of each other and must be screwed or bolted together inorder to secure the adjacent trays. The edge flanges space the traysapart. These screw or bolt type connections can add significant time andexpense to the installation of the Mischo system. Consequently, aroofing system that does not require screwed or bolted connectionsbetween adjacent trays is also desired. It is also desired to maximizecoverage of the roof by the trays.

The invention addresses these and other disadvantages of conventionalroofing systems.

SUMMARY

The disclosure provides a tray for a green roof system and a green roofsystem utilizing the tray. The tray includes a connecting lip to allowadjacent trays to be secured side-by-side together. The tray alsoincludes a securing device that penetrates the sidewalls of the tray,thereby providing a double locking system.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and advantages of the disclosurewill be more clearly understood from the following detailed descriptiontaken in conjunction with the accompanying drawings, in which:

FIG. 1 is a cross-sectional view of a green roof system in accordancewith some embodiments of the invention;

FIGS. 2A and 2B are perspective views of opposite sides of a tray foruse in a green roof system of the invention;

FIGS. 3 and 3A-B are cross-sectional views and FIG. 3C is an end view ofa method for connecting trays of a green roof system according to anembodiment of the invention;

FIG. 4 is a partial plan view of several trays connected together inaccordance with an embodiment of the invention;

FIG. 5 is a plan view of a single tray illustrating drain holes in thetray and the arrangement of complementary interconnecting male andfemale edges;

FIG. 6 is a partial cross-sectional view of the tray of FIG. 5illustrating drain hole covers over the drain holes in the tray;

FIGS. 7 and 7A-C are cross-sectional views illustrating trays connectedtogether according to an embodiment of the invention;

FIG. 8 is a plot of roof surface temperatures corresponding to varioustypes of roof coverings;

FIG. 9 is a plot of water retention corresponding to various depths ofsoil; and

FIG. 10 is a plot of roof surface temperatures in the summer and wintercorresponding to conventional roof coverings and roof coverings inaccordance with embodiments of the invention.

FIG. 11 is a cross-sectional view of an interlocking tray systemincluding wall anchor flashing interlocked with a male tray sidewall.

FIG. 12 is a cross-sectional view of an interlocking tray systemincluding wall anchor flashing interlocked with a female tray sidewall.

FIG. 13 is a cross-sectional view of an interlocking tray systemincluding walk pad trim flashing interlocked with a female traysidewall.

FIG. 14 is a cross-sectional view of an interlocking tray systemincluding walk pad trim flashing interlocked with a male tray sidewall.

FIG. 15 is a cross-sectional view of an interlocking tray systemincluding male and female tray edges.

FIGS. 16A and 16B are plan and cross-sectional views, respectively, of ahose gap according to some embodiments of the invention.

FIGS. 17A and 17B are plan and cross-sectional views, respectively, ofadjacent trays according to some embodiments of the invention.

FIG. 18 is a plan view of a hose retaining hook according to someembodiments of the invention.

FIGS. 19 and 20 are mutually orthogonal cross-sectional views of twojoined trays according to some embodiments of the invention.

FIGS. 21A and 21B are plan and partial cross-sectional views,respectively, of a tray illustrating drain holes according to someembodiments of the invention.

FIGS. 22A and 22B are cross-sectional views of perpendicular end capsaccording to some embodiments of the invention.

FIGS. 23A and 23B are cross-sectional views of parallel end capsaccording to some embodiments of the invention.

FIG. 24 is a plan view of a vegetation roofing system according to someembodiments of the invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Example embodiments are described below with reference to theaccompanying drawings. Many different forms and embodiments are possiblewithout deviating from the spirit and teachings of this disclosure andso the disclosure should not be construed as limited to the exampleembodiments set forth herein. Rather, these example embodiments areprovided so that this disclosure will be thorough and complete, and willfully convey the scope of the disclosure to those skilled in the art. Inthe drawings, the sizes and relative sizes of layers and regions may beexaggerated for clarity.

It will be understood that, although the terms first, second, third,etc. may be used herein to describe various elements, components,regions, layers and/or sections, these elements, components, regions,layers and/or sections should not be limited by these terms. These termsare only used to distinguish one element, component, region, layer orsection from another element, region, layer or section. Thus, a firstelement, component, region, layer or section discussed below could betermed a second element, component, region, layer or section withoutdeparting from the teachings of the disclosure.

The terminology used herein is for the purpose of describing particularexample embodiments only and is not intended to be limiting. As usedherein, the singular forms “a,” “an” and “the” are intended to includethe plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “comprises”and/or “comprising,” when used in this specification, specify thepresence of stated features, elements, and/or components, but do notpreclude the presence or addition of one or more other features,elements, components, and/or groups thereof.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneskilled in the art to which this disclosure pertains. It will be furtherunderstood that terms, such as those defined in commonly useddictionaries, should be interpreted as having a meaning that isconsistent with their meaning in the context of the relevant art andwill not be interpreted in an idealized or overly formal sense unlessexpressly so defined herein.

FIG. 1 is a cross-sectional view of a green roof system in accordancewith some embodiments of the invention.

Referring to FIG. 1, a green roof system comprises a plurality of trays11 disposed on a roof surface 19. The trays 11 contain an absorbentmedium 12 and may contain vegetation 18. The trays are connectedtogether along their adjoining edges by a connecting lip 13 and are heldfirmly together by a securing device 14. The securing device 14 maypenetrate connecting holes 15 in vertical sidewalls of the trays 11. Asshown in FIG. 1, excess water that is not absorbed by the absorbentmedium 12 may leave the trays 11 through drain holes 16 (see FIG. 4).

The trays 11 may be approximately square-shaped having four flat sidepanels or sidewalls 29 and a corrugated bottom wall 23. The trays 11 maybe semi-gloss black or green in color. The trays 11 may be composed ofpartially recycled 100 mil polypropylene. In this case, approximately25% of each tray 11 may be made from recycled polypropylene resin.Alternatively, the trays 11 may be composed of 75 to 150 (preferably100) mil polyethylene, approximately 25% of which may be recycled postindustrial polyethylene. The trays 11 may be manufactured by a vacuumforming technique. Alternatively, the trays 11 may be manufactured by aninjection molding process. The vertical side panels 29 of each tray 11may have a 5 degree draft or slope to enhance drainage. The trays 11 mayhave a standard depth of approximately 4⅝″.

The absorbent medium 12 may comprise both a soil mix and an absorbentmaterial. The soil mix may be an engineered, light-weight blendconsisting of inorganic and organic components. The absorbent materialmay be a super-absorbent water additive. As an example, ZEBA® fromAbsorbent Technologies, Inc. may be used as the absorbent material.

The vegetation 18 may be any type of plant that is suitable for theroof-top environment in the local climate. For example, the vegetationmay be a design mixture of fibrous succulents that can thrive in anon-irrigated, extensive rooftop environment. The vegetation 18 may beselected based upon its USDA hardiness zone classification and localrainfall conditions.

FIGS. 2A and 2B are perspective views of opposite sides of a tray foruse in a green roof system of the invention.

Referring to FIGS. 2A and 2B, the trays 11 include a plurality ofinterconnecting lips 13. The interconnecting lips 13 may be a generallyU-shaped edge 13A along a sidewall of a first tray configured to overlapa straight edge 13B along a sidewall of an adjacent tray. (“U-shaped”can include V-shaped.) As an example, a single tray 11 may be generallysquare in shape and have U-shaped edges 13A on two of its sidewalls. Thesidewalls of the tray 11 that have the straight edges 13B may bereferred to as male sidewalls 29M and the sidewalls that have theU-shaped edges 13A may be referred to as female sidewalls 29F. TheU-shaped edges 13A on the female sidewalls of a tray 11 may beconfigured to receive the straight edges 13B of adjacent trays such thatthe U-shaped edges 13A overhang the straight edges 13B of the adjacenttrays and extend inside the adjacent trays. Each square tray 11 may havetwo female sidewalls 29F which connect together about a notch 21 asshown in FIG. 2A. Opposite the female sidewalls 29F are two connectedmale sidewalls 29M. All of the sidewalls of the trays 11 may haveconnecting holes 15.

FIGS. 3 and 3A-C are cross-sectional views of a method for connectingtrays of a green roof system according to an embodiment of theinvention.

Referring to FIGS. 3 and 3A-C, a female sidewall 29F of a tray may beconnected to a male sidewall 29M of an adjacent tray by positioning theedge of the female sidewall 29F so as to overlap the edge of the malesidewall 29M of the adjacent tray. As best shown in FIG. 3, the U-shapededge 13A of the female sidewall 29F may extend inside the adjacent tray.The facing sidewalls of adjoining trays may be further secured togetherby the securing device 14. The securing device 14 may penetrateconnecting holes 15 in the adjacent sidewalls of the adjacent trays. Asan example, the securing device 14 may be a quick-lock fastener. Thequick-lock fastener is inserted through the connecting holes 15 and thenactuated to secure the adjacent trays 11 together. An example of aquick-lock fastener suitable for this application is a Fastex Tuflok™.In some cases, both the interconnecting lip 13 and the securing device14 are used to secure adjacent trays together. This configuration may bereferred to as a ‘double locking system’. However, in some cases, thesecuring device 14 is not used, so that only the interconnecting lip 13is used to secure adjacent trays together.

FIG. 4 is a partial plan view of several trays connected together inaccordance with an embodiment of the invention.

Referring to FIG. 4, four trays 11 are connected together as describedwith reference to FIG. 3 above. The trays 11A, 11B, 11C, and 11D areconnected together in a grid-type configuration thereby allowing largeportions of a roof structure to be covered by a system of interconnectedtrays. The notch 21 in the corner of tray 11A accommodates the maleedges at the adjacent corners of trays 11B and 11D. Since aninterconnecting lip 13 is used to secure each of the adjacent traystogether, there is no gap between sidewalls of adjacent trays.Therefore, the roofing system of the invention provides better roofsurface area utilization and coverage than conventional systems. Theinterconnecting lip design of the trays also prevents soil mixture fromspilling in between adjacent trays, thereby preventing other problemsassociated with conventional systems. Further, the interconnecting lipdesign of the invention provides easy installation that does not requireinstallation of screws or bolts.

Each of the trays 11 contains multiple drain holes 16, each having adrain hole cover 17. The drain hole cover 17 may be a screen forpreventing the absorbent medium 12, or roots associated with thevegetation 18, from leaving the tray 11 through the drain hole 16.

FIG. 5 is a plan view of a single tray illustrating drain holes in thetray and the arrangement of complementary interconnecting male andfemale edges. FIG. 6 is a partial cross-sectional view of the tray ofFIG. 5 illustrating drain hole covers over the drain holes in the tray.

Referring to FIGS. 1, 5 and 6, each tray 11 comprises a corrugatedbottom panel 23. The bottom panel 23 of each tray may be composed ofeleven, parallel, raised ribs 26 and ten, parallel, recessed flutes 25.Some of the ribs 26 may have drain holes 16. The tray 11 may have ninedrain holes 16 arranged in a ‘St Andrews’ cross-type pattern. Each drainhole 16 may have an approximately ⅜″ diameter. The ribs 26 and flutes 25may be ¾″ in width. Each flute 26 may be approximately ⅝″ deep. Thepurpose of the flutes 25 is to act as a cistern and store water to aidhydration of the growing media during extensive dry periods. See FIG. 1showing retained water in the flutes. Other numbers, sizes, andarrangements of the drain holes 16, the ribs 26, and the flutes 25 arewithin the spirit and scope of the invention.

Referring to FIG. 6, a drain hole cover 17, as described above withrespect to FIG. 4, covers each of the drain holes 16 in the tray 11. Asan example, the drain hole cover 17 may be a mesh screen. The drain holecover may be secured to the flute 25 over the drain hole 16 and may bemade of any suitable material including copper, stainless steel, oranother metal or metal alloy or a polymeric or glass fiber mesh. Thedrain hole cover 17 may be secured to the flute 26 over the drain hole16 using a glue or adhesive material. Alternatively, the drain holecover 17 may be molded into the flute 25 over the drain hole 16. Forexample, a drain hole cover 17 may be placed into an injection mold sothat when the tray 11 is manufactured, the drain hole cover 17 isintegrally molded into the tray. According to preferred embodiments, thedrain hole cover 17 is a mesh screen made of 0.011″ copper or stainlesssteel wire or other mesh material and is molded into the tray 11.

FIGS. 7 and 7A-C are cross-sectional views illustrating trays connectedtogether according to an alternative embodiment of the invention.

Referring to FIGS. 7 and 7A-C, the sidewalls of the trays 11 may includea protruded portion 27 downwardly adjacent to lip 13 along the upperedge thereof. The protruded portion 27 may be a rounded protrusion orbulge extending inwardly from the plane of the sidewalls of the tray 11.Adjacent trays are positioned such that the interconnecting lip 13 ofthe female sidewall 29F of a first tray overlaps the male sidewall 29Mof a second tray. Then, a U-shaped spring clip 28 may be installed overthe interconnecting lip 13 so as to engage with the protruded portions27 and thereby secure the adjacent trays together.

FIG. 8 is a plot of roof surface temperatures corresponding to varioustypes of roof coverings, from A. Dürr, Roof Greening: An EcologicalBalance (1995), republished in U.S. Department of Energy, FederalTechnology Alert Publication DOE/EE-0298, September 2004.

As shown in FIG. 8, when the invention is utilized, the roof surfacetemperature varies only about 25 degrees over a 48-hour period. However,when conventional roof coverings are used, the roof surface temperaturevaries between about 50 and 110 degrees, depending on the type of roofcovering used. Consequently, roof coverings in accordance with theinvention can provide significant energy savings by minimizing thevariation of roof surface temperature and the corresponding temperatureinside a building.

FIG. 9 is a plot of water retention corresponding to various depths ofsoil, from A. Dürr.

As shown in FIG. 9, increased soil depth leads to improved waterretention capabilities. When the trays of the invention are manufacturedwith the standard depth of 4⅝″, the water retention of the trayscorresponds to the 71% data point on the graph. Conventional methodswith less soil depth have significant reduction in water retention asshown by the 58% and 67% data points in the graph.

FIG. 10 is a plot from A. Dürr of roof surface temperatures in thesummer and winter corresponding to conventional roof coverings and greenroof coverings in general, per A. Dürr.

As shown in FIG. 10, during the summer, the roof surface temperature ofa roof employing the invention only varies about 20 degrees over a24-hour period. In contrast, the roof surface temperature of a roofemploying a conventional roof covering varies about 100 degrees over a24-hour period in the summer. During the winter, the roof surfacetemperature of a roof employing the invention also only varies about 20degrees over a 24-hour period. The roof surface temperature of a roofemploying a conventional roof covering varies about 50 degrees under thesame conditions.

As described above, the interlocking tray system of the inventionprovides gap-less coverage of roof surfaces without installation ofscrews or bolts. This allows better roof surface area utilization andprevents the adverse effects of soil mixture spillage between adjacenttrays. Utilizing the green roof system of the invention, water retentioncan be maximized and roof surface temperature variation can beminimized. Consequently, the green roof system of the invention providesreduced energy costs, reduced runoff during rainy periods, andenvironmental advantages, such as increased green space in commercial orother populated areas. Buildings employing the green roof system of theinvention may also realize reduced noise pollution due to thesound-dampening qualities of the vegetation and the absorbent medium inthe trays.

FIG. 11 is a cross-sectional view of an interlocking tray systemincluding wall anchor flashing interlocked with a male tray sidewall.FIG. 12 is a cross-sectional view of an interlocking tray systemincluding wall anchor flashing interlocked with a female tray sidewall.

Referring to FIGS. 11 and 12, an interlocking tray system according toan embodiment of the invention includes a wall anchor flashing 31. Thewall anchor flashing 31 may be secured to a parapet wall 39 using afastener 38. The wall anchor flashing 31 overhangs a male sidewall 29M(FIG. 11) or a female sidewall 29F (FIG. 12) of a tray 11. The wallanchor flashing 31 may include a connecting hole 35 and a securingdevice 34. The securing device 34 penetrates the connecting hole 35 inthe wall anchor flashing 31 and the corresponding connecting hole 15 inthe tray 11 to secure the wall anchor flashing 31 to the tray 11.

FIG. 13 is a cross-sectional view of an interlocking tray systemincluding walk pad trim flashing interlocked with a female traysidewall. FIG. 14 is a cross-sectional view of an interlocking traysystem including walk pad trim flashing interlocked with a male traysidewall.

Referring to FIGS. 13 and 14, an interlocking tray system according toan embodiment of the invention includes a walk pad wall flashing 41, awalk pad 48, and a walk pad trim flashing 42. The walk pad wall flashing41 may be secured to a parapet wall 39 using a fastener 38. As shown inFIG. 13, a male edge 43M of the walk pad trim flashing 42 interlockswith a U-shaped edge 13A of a female sidewall 29F of a tray 11. As shownin FIG. 14, a female edge 43F of the walk pad trim flashing 42interlocks with a straight edge 13A of a male sidewall 29M of a tray 11.The walk pad trim flashing 42 may include a connecting hole 45 and asecuring device 44. The securing device 44 penetrates the connectinghole 45 in the walk pad trim flashing 42 and the correspondingconnecting hole 15 in the tray 11 to secure the walk pad trim flashing42 to the tray 11.

FIG. 15 is a cross-sectional view of an interlocking tray systemincluding male and female tray edges.

Referring to FIG. 15, an interlocking tray system according to anembodiment of the invention includes a male tray edge 51M and/or afemale tray edge 51F. The male tray edge 51M interlocks with a U-shapededge 13A of a female sidewall 29F of a tray 11. The female tray edge 51Finterlocks with a straight edge 13B of a male sidewall 29M of a tray 11.The male and female tray edges, 51M and 51F, may each include aconnecting hole 55 and a securing device 54. The securing device 54penetrates the connecting hole 55 and the corresponding connecting hole15 in the tray 11 to secure the male and female tray edges, 51M and 51F,to the tray 11.

FIGS. 11 through 15 illustrate embodiments of the invention for securingan interlocking tray system to various rooftop elements such as HVACcomponents, parapet walls, and vents. Securing the interlocking traysystem to the rooftop elements allows the system to integrate withexisting rooftop configurations and prevents wind uplift from displacingand/or damaging trays.

FIGS. 16A and 16B are plan and cross-sectional views, respectively, of ahose gap according to some embodiments of the invention.

Referring to FIGS. 16A and 16B, a female sidewall 29F of a tray 11 caninclude a hose gap 30. The hose gap 30 can be an indentation from thesubstantially flat top surface of the female sidewall 29F. The hose gap30 is configured to allow an irrigation hose to lay across the edge ofthe tray. The hose gap 30 can be disposed above the connecting hole 15so that a hook can be used to retain an irrigation hose in the hose gap30, as described below with respect to FIGS. 19 and 20. The hose gap 30may have a width of approximately ⅝″ and a height of approximately ⅝″from the top of the female sidewall 29F. The hose gap 30 can have asubstantially semi-circular bottom so that an irrigation hose can besupported in the hose gap 30.

FIGS. 17A and 17B are plan and cross-sectional views, respectively, ofadjacent trays according to some embodiments of the invention.

Referring to FIGS. 17A and 17B, a male sidewall 29M of a tray 11 canalso include a hose gap 30. The hose gap 30 can be an indentation fromthe substantially flat top surface of the male sidewall 29M. When a malesidewall 29M and a female sidewall 29F are joined, corresponding hosegaps 30 are aligned so that an irrigation hose can be disposed in thehose gaps 30 of adjacent trays 11.

FIG. 18 is a plan view of a hose retaining hook according to someembodiments of the invention.

Referring to FIG. 18, a hose retaining hook 40 includes a mountingportion 42, a mounting hole 44, and a hook portion 46. The mountingportion 42 can be placed against the female sidewall 29F of a tray 11such that the mounting hole 44 is aligned with the connecting hole 15. Asecuring device 14 can then be used to secure the retaining hook 40 tothe tray 11 when adjacent trays 11 are joined together, as describedabove with respect to FIGS. 3 and 3A-C. The hook portion 46 can bepositioned such that an irrigation hose is retained between the hookportion 46 and the hose gaps 30 of adjacent trays 11.

FIGS. 19 and 20 are mutually orthogonal cross-sectional views of twojoined trays according to some embodiments of the invention.

Referring to FIGS. 19 and 20, two trays 11 may be joined together by asecuring device 14 as described above with respect to FIGS. 3 and 3A-C.The two trays 11 each include a hose gap 30 and the hose gaps 30 arealigned with each other. An irrigation hose 35 is disposed across thetwo trays 11 and in the hose gaps 30. The irrigation hose 35 includes aplurality of drip emitters 37. The drip emitters 37 may be spaced apartalong the irrigation hose 35 at approximately 4″ to 12″ intervals. Ahose retaining hook 40 engages the irrigation hose 35 and retains theirrigation hose 35 in the hose gaps 30. The securing device 14penetrates the hose retaining hook 40 and holds the hose retaining hook40 securely to the female side 29F of the tray 11.

FIGS. 21A and 21B are plan and partial cross-sectional views,respectively, of a tray illustrating drain holes according to someembodiments of the invention.

Referring to FIGS. 21A and 21B, a bottom panel 23 of a tray 11 mayinclude a plurality of raised ribs 26 and recessed flutes 25. One ormore of the raised ribs 26 may include a drain hole array 62. The drainhole array 62 may comprise 13 equally-spaced drain holes arranged in aregular pattern. The drain holes in the drain hole array 62 may becircular holes with a diameter of approximately 1/16″.

Additionally, one or more of the recessed flutes 25 may include a rootdrain hole 64. The root drain hole 64 may be substantially circular witha diameter of approximately 1/16″. The bottom panel 23 may include aplurality of root drain holes 64 positioned along a centerline of thetray 11. The root drain holes 64 may be disposed approximately ⅛″ fromeach of the raised ribs 26. Alternatively, the root drain holes 64 maybe disposed next to only some of the raised ribs 26 (for instance, oneroot drain hole 64 may be disposed in each of the recessed flutes 25.The root drain holes 64 may be configured so as to prevent excessivewater accumulation in the recessed flutes 25 from causing root rot orother damage to vegetation in the tray 11.

Depending on the surface area that is to be covered by a vegetationroofing system, it may be difficult to use a whole number of trays 11 tocover the area. In this case, it may be desirable to trim a number oftrays 11 to match the area to be covered. Consequently, end caps can beused to close off the ends of the trimmed or partial trays so thatvegetation can be retained in the partial trays and the appropriatedrain conditions can be maintained.

Depending on the configuration of the vegetation roofing system, it maybe desirable to trim some trays perpendicular to the raised ribs in thebottom panel and to trim some trays parallel to the raised ribs. Forexample, if trays are arranged such that the raised ribs of adjacenttrays are perpendicular to each other, when several trays along a sideof the vegetation roofing system are trimmed, the resulting partialtrays will alternate being perpendicular and parallel with the raisedribs. Therefore, end caps can be provided to accommodate partial traysthat are trimmed parallel to the raised ribs and end caps to accommodatepartial trays that are trimmed perpendicular to the raised ribs.

FIGS. 22A and 22B are cross-sectional views of perpendicular end capsaccording to some embodiments of the invention.

Referring to FIGS. 22A and 22B, a perpendicular end cap 70 includes avertical side panel 72, a connecting lip 73, a plurality of raisedportions 76, and a plurality of recessed portions 78. The connecting lip73 may be either a generally U-shaped edge or a straight edge, similarto the connecting lips 13 described above with respect to FIGS. 2A andB. One or more of the raised portions 76 may be secured to a partialtray 11P by a securing device 74.

FIGS. 23A and 23B are cross-sectional views of parallel end capsaccording to some embodiments of the invention.

Referring to FIGS. 23A and 23B, a parallel end cap 80 includes avertical side panel 82, a connecting lip 83, a horizontal member 86, anda trough 88. The connecting lip 83 may be either a generally U-shapededge or a straight edge, similar to the connecting lips 13 describedabove with respect to FIGS. 2A and B. The horizontal member 86 may besecured to a partial tray 11P by a securing device 84.

FIG. 24 is a plan view of a vegetation roofing system according to someembodiments of the invention.

Referring to FIG. 24, a vegetation roofing system includes a pluralityof trays 11, a plurality of irrigation hoses 35, and a walk pad 48. Thetrays 11 may include some partial trays 11P and end caps as describedabove with respect to FIGS. 22A-23B. As an example, the vegetationroofing system is shown as including perpendicular end caps 70 connectedto partial trays 11P. The irrigation hoses 35 extend across multipletrays 11 and are supported in the hose gaps 30 of the trays. The trays11 may include hose retaining hooks 40 to secure the irrigation hoses 35in place. The trays 11 may also include drain hole arrays 62 and rootdrain holes 64.

The foregoing is illustrative of the invention and is not to beconstrued as limiting thereof. Although a few example embodiments of theinvention have been described, those skilled in the art will readilyappreciate that many modifications are possible in the exampleembodiments without materially departing from the novel teachings andadvantages of the invention. For example, the trays could be hexagonal,with alternating male and female sidewalls. Accordingly, all suchmodifications are intended to be included within the scope of theinvention as defined in the following claims.

1. A vegetation roofing tray, comprising: a bottom panel; at least fourvertical side panels; and at least one drain hole; wherein two of thevertical side panels include a U-shaped upper edge and two of thevertical side panels include a straight upper edge mutually arranged sothat the straight upper edge can be received in the U-shaped upper edgeof an adjacent tray, and wherein at least one of the U-shaped upperedges and at least one of the straight upper edges comprise a hose gap.2. The tray of claim 1, wherein at least two of the vertical side panelscomprise a connecting hole and wherein the connecting holes are disposedbelow the hose gaps.
 3. The tray of claim 1, wherein the bottom panelcomprises: a plurality of raised ribs; and a plurality of recessedflutes.
 4. The tray of claim 3, wherein the at least one drain holecomprises a drain hole array disposed on at least one of the raisedribs.
 5. The tray of claim 3, wherein the at least one drain holecomprises at least one root drain hole disposed in at least one of therecessed flutes.
 6. The tray of claim 1, further comprising an absorbentmedium and vegetation.
 7. The tray of claim 6, wherein the absorbentmedium includes a soil mixture and an absorbent material.
 8. Avegetation roofing system, comprising: a first tray; and a second trayadjacent to the first tray; each of the first tray and the second trayincluding: a bottom panel; a plurality of vertical side panels, whereinat least one of the vertical side panels includes a hose gap; and atleast one drain hole, wherein an interconnecting lip couples adjacentvertical side panels of the first and second trays such that the hosegap of the first tray corresponds to the hose gap of the second tray;and an irrigation hose at least partially disposed in the hose gaps ofthe first and second trays.
 9. The system of claim 8, further comprisinga securing device penetrating adjacent connecting holes of the first andsecond trays, wherein the connecting holes are disposed below the hosegaps.
 10. The system of claim 9, further comprising a hose retaininghook, wherein the securing device penetrates the hose retaining hook andthe hose retaining hook is configured to engage the irrigation hose. 11.The system of claim 8, wherein the bottom panels of the first and secondtrays comprise: a plurality of raised ribs; and a plurality of recessedflutes.
 12. The system of claim 11, wherein the drain holes in the firstand second trays comprise a drain hole array disposed on at least one ofthe raised ribs.
 13. The system of claim 11, wherein the drain holes inthe first and second trays comprise at least one root drain holedisposed in at least one of the recessed flutes.
 14. The system of claim8, further comprising: a partial tray adjacent to one of the first andsecond trays; and at least one end cap.
 15. The system of claim 14,wherein the end cap comprises a vertical side panel including a U-shapedupper edge.
 16. The system of claim 14, wherein the end cap comprises avertical side panel including a straight upper edge.
 17. The system ofclaim 14, wherein the end cap comprises: a vertical side panel; and aplurality of recessed portions; and a plurality of raised portions,wherein at least one of the raised portions is attached to a raised ribof the partial tray by a securing member.
 18. The system of claim 14,wherein the end cap comprises: a vertical side panel; a trough; and ahorizontal member, wherein the horizontal member is attached to a raisedrib of the partial tray by a securing member.
 19. A method ofinterconnecting green roof trays, the method comprising: providing aU-shaped upper edge on a sidewall of a first tray; providing a straightupper edge on a sidewall of a second tray; and positioning the firsttray adjacent to the second tray so that the U-shaped upper edgeoverhangs the straight edge and the U-shaped upper edge extends into thesecond tray.
 20. The method of claim 19, further comprising: providing afirst connecting hole in the sidewall of the first tray; providing asecond connecting hole in the sidewall of the second tray; andinstalling a securing device so that the securing device penetrates thefirst and second connecting holes.
 21. The method of claim 20, furthercomprising: providing a first hose gap in the sidewall of the firsttray; providing a second hose gap in the sidewall of the second tray;and installing an irrigation hose in the first and second hose gaps. 22.The method of claim 21, further comprising engaging a hose retaininghook with the irrigation hose, wherein the securing device penetratesthe hose retaining hook.